#ifndef _TAO_HONG_MIN_20130810_MD5_H_
#define _TAO_HONG_MIN_20130810_MD5_H_

#include <string>

typedef struct tagMD5_CTX
{
	unsigned int count[2];
	unsigned int state[4];
	unsigned char buffer[64];
} MD5_CTX;

#define F(x,y,z) ((x & y) | (~x & z))
#define G(x,y,z) ((x & z) | (y & ~z))
#define H(x,y,z) (x^y^z)
#define I(x,y,z) (y ^ (x | ~z))
#define ROTATE_LEFT(x,n) ((x << n) | (x >> (32-n)))
#define FF(a,b,c,d,x,s,ac) \
          { \
          a += F(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }
#define GG(a,b,c,d,x,s,ac) \
          { \
          a += G(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }
#define HH(a,b,c,d,x,s,ac) \
          { \
          a += H(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }
#define II(a,b,c,d,x,s,ac) \
          { \
          a += I(b,c,d) + x + ac; \
          a = ROTATE_LEFT(a,s); \
          a += b; \
          }

class MD5
{
public:
	static std::string Encode(const std::string & strsrc);
private:
	static void MD5Init(MD5_CTX *context);
	static void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen);
	static void MD5Final(MD5_CTX *context, unsigned char digest[16]);
	static void MD5Transform(unsigned int state[4], unsigned char block[64]);
	static void MD5Encode(unsigned char *output, unsigned int *input, unsigned int len);
	static void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len);
	static int  md5_in(unsigned char *src, unsigned char *dst);
};

#endif	/* _TAO_HONG_MIN_20130810_MD5_H_ */
